Responses
We know the present Sebastian not the past because in "book of circus" William said that Sebastian used to eat a lot so maybe he tricked people to after eat their souls.
I think it's Sebastian because of the mark but he's using an other methode
But it can also not be Sebastian but another demon and I'll love that
I don’t think it’s Sebastian because Sebastian can only be summoned through life sacrifice, this guy just appears out of nowhere and starts offering people wishes? He didn’t even explain how the contract works.